1. Field of Invention
The present invention relates to insulating ladle covers with refractory ceramic fiber modules.
2. Description of the Prior Art
It is known to be desirable to install insulated covers over ladles used in steelmaking to prevent heat loss. When the ladle contained a bath of molten steel, an insulated ladle cover suppressed heat loss from the steel bath surface. Once the molten steel had been poured, the cover conserved heat in the lining of the ladle. Although vulnerable to slag or metal contact refractory ceramic fibers offered certain advantages in insulating ladle covers, namely light weight, resilience and insulating value.
So far as is known to applicant, ceramic fibers have been installed in ladle covers in several ways. One method involved laying a refractory ceramic fiber blanket strip on one side edge in a spiral fashion onto a lower surface of a round ladle lid and gluing the side edge to the lid. Metal anchors were placed at selected positions to facilitate the gluing and in an attempt to put the blanket strip in some degree of compression. Installation of the spiral wrapped blanket on the lid was time consuming and relatively difficult. Other lining methods included the use of standard refractory ceramic fiber modules of block form and various edge-stacked methods. In all of these methods, the ceramic fiber was by necessity of uniform thickness over the entire surface of the lid, placing excessive insulation at the center of the ladle lid which would have been better used in the high wear area of the ladle rim.
It was also difficult in these prior art ladle cover fiber linings to repair the insulation in the area of the rim seal independently of the center portion. Repair usually required a complete relining of the insulative cover. Another problem with prior art ladle cover seals was the requirement of an outside diameter retainer ring to support the fiber material. Located near the area of contact with the ladle rim during sealing, the retainer ring was susceptible to heat leaks, resulting in warping or oxidation of the steel.